Alert archive / Texas / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 83, NWS Austin/San Antonio, TX

May 21, 2011Burnet County, Travis County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 21, 2011, 7:10 PM CDT for Burnet County, Travis County, Williamson County, Texas. It was in force for 50 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 21, 2011, 7:10 PM CDT (00:10 UTC)
Expired
May 21, 2011, 8:00 PM CDT
In force
50 min
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon

Counties Burnet County, TX, Travis County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 61 km from the middle of the area, began a volume at 00:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 21, 7:11 PM CDTHAIL 1Bertram, TX
May 21, 7:30 PM CDTFUNNEL CLOUD5 W Bertram, TX
May 21, 7:32 PM CDTFUNNEL CLOUDBertram, TXSPOTTER NEAR BERTRAM SEES A WALL CLOUD ROTATING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 21, 1:45 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 0.2 hours before the alert went out and 244 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3908 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 116 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3908 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
978 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
3.2
Supercell composite
16.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

163 
WUUS54 KEWX 220010
SVREWX
TXC053-453-491-220100-
/O.NEW.KEWX.SV.W.0083.110522T0010Z-110522T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
710 PM CDT SAT MAY 21 2011

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL BURNET COUNTY...
  EXTREME NORTHWESTERN TRAVIS COUNTY...
  WEST CENTRAL WILLIAMSON COUNTY...

* UNTIL 800 PM CDT.

* AT 705 PM CDT...NWS METEOROLOGISTS HAVE DETECTED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  BERTRAM...AND MOVING SOUTHEAST AT 20 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE OATMEAL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

&&

LAT...LON 3074 9787 3057 9800 3072 9823 3087 9812
TIME...MOT...LOC 0010Z 303DEG 19KT 3074 9808

$$
2 follow-up statements
547 
WWUS54 KEWX 220028
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
728 PM CDT SAT MAY 21 2011

TXC053-453-491-220100-
/O.CON.KEWX.SV.W.0083.000000T0000Z-110522T0100Z/
BURNET TX-WILLIAMSON TX-TRAVIS TX-
728 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR EXTREME NORTHWESTERN TRAVIS...WEST CENTRAL WILLIAMSON AND CENTRAL
BURNET COUNTIES...

AT 719 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND DAMAGING
WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR BERTRAM AND 
NEAR THE INTERSECTION OF HIGHWAY 29 AND FM 1174...MOVING SOUTHEAST 
AT 20 MPH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

&&

LAT...LON 3074 9787 3057 9800 3072 9823 3087 9812
TIME...MOT...LOC 0026Z 302DEG 19KT 3074 9803

$$
787 
WWUS54 KEWX 220042
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
742 PM CDT SAT MAY 21 2011

TXC453-220052-
/O.CAN.KEWX.SV.W.0083.000000T0000Z-110522T0100Z/
TRAVIS TX-
742 PM CDT SAT MAY 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR EXTREME NORTHWESTERN TRAVIS
COUNTY IS CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

LAT...LON 3074 9787 3065 9794 3075 9817 3087 9812
TIME...MOT...LOC 0042Z 279DEG 20KT 3077 9801

$$

TXC053-491-220100-
/O.CON.KEWX.SV.W.0083.000000T0000Z-110522T0100Z/
BURNET TX-WILLIAMSON TX-
742 PM CDT SAT MAY 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR WEST CENTRAL WILLIAMSON AND CENTRAL BURNET COUNTIES...

AT 736 PM CDT...NWS METEOROLOGISTS CONTINUED TO DETECT A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND DAMAGING
WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR BERTRAM...
MOVING EAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS
OF THE INDICATED COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT
SATURDAY EVENING FOR SOUTH CENTRAL TEXAS.

&&

LAT...LON 3074 9787 3065 9794 3075 9817 3087 9812
TIME...MOT...LOC 0042Z 279DEG 18KT 3077 9801

$$

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 7:27 PM CDTTornado WarningEWXBurnet, Williamson33 min
May 21, 7:44 PM CDTSevere Thunderstorm WarningEWXBurnet, Williamson46 min
May 21, 7:50 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano40 min
May 21, 7:59 PM CDTTornado WarningEWXBurnet, Williamson31 min
May 21, 8:08 PM CDTAreal Flood AdvisoryEWXBurnet, Williamson112 min
May 21, 8:11 PM CDTTornado WarningEWXBurnet, Llano34 min
May 21, 8:27 PM CDTSevere Thunderstorm WarningEWXWilliamson48 min
May 21, 8:27 PM CDTTornado WarningEWXWilliamson33 min
May 21, 8:32 PM CDTSevere Thunderstorm WarningEWXBurnet43 min
May 21, 8:44 PM CDTTornado WarningEWXBurnet31 min
May 21, 8:59 PM CDTTornado WarningEWXWilliamson31 min
May 21, 9:14 PM CDTSevere Thunderstorm WarningEWXBurnet, Williamson46 min

Nearby

Severe Thunderstorm Warnings in Texas, 2011Every severe thunderstorm warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.